DEQ-CFW_00062047

(KW
DuPont Automotive
Mr. Gregory Nizich
NC DEHNR - DEM
Water Quality Section
Permits & Engineering Unit
P. O. Box 29535
Raleigh, NC 27626-0535
DLP IV t�,
MAR 6 1996
�EyNV(,, M{A�IIA(-stir,. -NT
FA �/C1T6VILL
RE: NPDES Permit No. NC0003573
Reclassification of DuPont -Fayetteville Wastewater Treatment Facility
Dear Mr. Nizich,
DuPont Automotive
P.O. Drawer Z
Fayetteville, NC 28302
March 4, 1996
A letter dated February 26, 1996, from Mr. Michael Wicker (DEHNR-Fayetteville Regional
Office) states that this site's Wastewater Treatment Plant (WWTP) will be reclassified from a
Class III to a Class IV facility upon the renewal of the referenced NPDES Permit.
In reviewing the points allocated to the WWTP in determining this reclassification, I believe two
items totaling four points were incorrectly included. Without these four points, the facility
assessment would total 65 points, and the WWTP would remain a Class III facility.
After you have reviewed this letter, please call me so that we can discuss this issue. Assuming
that you agree with my following assessment, we could then discuss what steps would be needed
to reverse this reclassification.
PRE -DIGESTER TANK
The Pre -Digester Tank is a 250,000 gallon above -ground tank with a diffused air system, and
acts as the first stage of the two -stage activated sludge system. The Pre -Digester Tank receives
the untreated influent from the Equalization Basin. Returned activated sludge (RAS) and the
diffused air provides the initial biological treatment. The effluent from this tank is sent to the
1.7-million gallon Aeration Tank, which is the second and final stage of activated sludge. The
RAS from the two clarifiers is sent to both the Pre -Digester and the Aeration Tank to introduce
the biological microbes into the untreated and partially treated wastewater respectively.
The Facility Assessment counted the Pre -Digester Tank as a "Preaeration Unit" [Item 3(g)] under
the Preliminary Units/Processes Category. Per definition No. 31 of NCAC Title 15A\Chapter8\
E I do Pont de Nemours and Company ® Printed on Recycled Paper
Z-544 Rev B/M
DEQ-CFW 00062047

Mr. Gregory Nizich
NC DEHNR - DEM
March 4, 1996
Page 2
Rule .0004, "Preaeration" is "a tank constructed to provide aeration prior to primary treatment."
In doing so, two (2) separate points were counted for this tank.
As described above, the Pre -Digester Tank provides activated sludge biological trreatment
(secondary treatment), and should have been counted as part of the Carbonaceous Stage -Diffused
Air System [Item 5(a)(i)] under the Secondary Treatment Units/Processes Category, along with
the Aeration Tank. The ten (10) points for this item should have covered both the Pre -Digester
Tank and the Aeration Tank.
Therefore, I request that the Pre -Digester Tank be counted under Item 5(a)(i), and the two (2)
points added for "Preaeration" be eliminated.
SLUDGE DISPOSAL
The site's wasted excess sludge is dried via steam -heated dryers, and then disposed of at the BFI
(Subpart D) Landfill in Sampson County.
The Facility Assessment counted the sludge disposal as "Land Application (surface and
subsurface) by contracting to a land application operator or landfill operator who holds the land
application permit or landfill permit" [Item 8(b)] under the Residuals Utilization/Disposal
Category. In doing so, two (2) separate points were counted for this disposal activity.
Item 8(b) is defined by Definition No. 22a of NCAC Title 15A\Chapter8\Rule .0004, which
states in part:
"(22) Land application:
(a) Sludge Disposal. A final sludge disposal method by which wet sludge may be
applied to land either by spraying on the surface or by subsurface injection"
I believe that our sludge disposal is outside of this definition. Our dried sludge is not wet and
could not physically be sprayed on the surface nor injected underground. If the sludge does not
meet Definition 22a, then our sludge disposal should not be counted under Item 8(b).
Therefore, I request that the two (2) points, allocated for the sludge disposal activity counted
under Item 8(b) be eliminated.
SUMMARY
I hope that you will agree that the above two items have been incorrectly categorized, and that the
four total points given for those items should be removed from the classification point total,
DEQ-CFW 00062048

Mr. Gregory Nizich
NC DEHNR - DEM
March 4, 1996
Page 3
resulting in a new point total of 65 points, and a maintaining of the current Class III Facility
classification for this site's WWTP.
Please feel free to call me at [phone] to discuss this matter.
cc: Mr. Michael Wicker, DEHNR, Fayetteville
Mr. Ken Averitte, DEHNR, Fayetteville
Mr. John E. Hagle, DuPont
Mr. Robert J. Geddie, DuPont
Michael E. Johnson
Environmental Coordinator
DEQ-CFW 00062049